The Trump administration is preparing to evaluate immigration judges against new benchmarks. The goal is to speed through a backlog of more than 600,000 cases in U.S. immigration courts. Judges warn the change could hurt public confidence and violate the right to due process. NPR's Carrie Johnson reports.

CARRIE JOHNSON, BYLINE: President Trump and his Cabinet members often say the immigration system is broken. In a speech last week, Attorney General Jeff Sessions highlighted the problem.

(SOUNDBITE OF ARCHIVED RECORDING)

JEFF SESSIONS: We have a crisis at our borders, and we intend to fix it. Success is our goal.

JOHNSON: Over 20 years in the U.S. Senate, Sessions supported tough immigration measures. Now, as the country's top law enforcement officer, Sessions can make changes from inside the executive branch.

(SOUNDBITE OF ARCHIVED RECORDING)

SESSIONS: It's something I've believed in and fought for for many years, and I feel honored to have the opportunity to participate in it.

JOHNSON: Among other things, the attorney general oversees the nation's immigration judges. And big changes could be coming their way. A recent White House wish list mentions the idea of performance metrics for judges. The Justice Department says it's developing new benchmarks for immigration courts to, quote, "increase productivity and reduce the pending caseload without compromising due process." But advocates for immigrants warn that quotas could be a disaster. Heidi Altman works on policy issues at the National Immigrant Justice Center.

HEIDI ALTMAN: The administration has been very explicit that it perceives immigration judges as a mechanism to expedite and pursue deportations. And that's a dangerous misunderstanding of the role of the immigration judge.

JOHNSON: The courts are backed up, more than 2,000 pending cases for every immigration judge. But the National Association of Immigration Judges says the way to solve that problem is to hire more judges, not put pressure on the people who are already handling big caseloads. Judge Dana Leigh Marks is a spokeswoman from the immigration judges' group.

DANA LEIGH MARKS: The last thing on a judge's mind should be pressure that you're disappointing your boss or, even worse, risking discipline because you are not working fast enough.

JOHNSON: Immigration judges operate under a collective bargaining agreement with the Justice Department, and DOJ officials have signaled they want to renegotiate that contract soon. For Marks and many of her colleagues, that move threatens the idea they are neutral decision-makers. And she says it could leave immigrants with the idea the system is stacked against them.

MARKS: The imposition of numerical metrics would put judges in an untenable position and would undermine confidence in our independence by the public we serve.